Manufacture | AlzChem

Manufacture

Calcium cyanamide manufacture

Limestone, coal and atmospheric nitrogen are the natural raw materials from which calcium cyanamide is manufactured. Regular investment and constant improvement of the production process ensures a modern, efficient and environmentally friendly manufacture of the specialty fertilizer.

 

Calcium cyanamide is manufactured in three stages:

  1. Stage one: Manufacture of burnt lime (also known as quick lime)
    Limestone (CaCO3), mined from natural deposits, is crushed and then processed in coke or oil-fired furnaces to form burnt lime.

     

  2. Stage two: Manufacture of carbide
    The burnt lime obtained as a result of this process is fed into carbide furnaces together with coke and anthracite, which provide a supply of carbon.  Calcium carbide is produced in these ovens at temperatures above 2,000°C, with electrical energy generating the heat required.  The carbon monoxide generated during this manufacturing process is collected and used as a starting material for further chemical reactions.  

     

  3. Stage three: Manufacture of calcium cyanamide
    In the last stage of the synthesis nitrogen gas is passed through finely-ground calcium carbide which has a temperature of approx. 1,100°C. This chemically binds the nitrogen, resulting in calcium cyanamide. The carbon released during this reaction gives the calcium cyanamide its black color.  The nitrogen gas necessary is recovered in a proprietary air separation plant using the Linde method.

The so-called technical calcium cyanamide coming from the rotary kilns is further processed for use in agriculture and horticulture.  The ground-calcium cyanamide is produced by finely grinding the product.  PERLKA® (= pearled calcium cyanamide) is produced from the ground product by granulation, and adjusted to the defined grain size by sieving.